iMach3 P2-S Stops Working

Hi all,

I've been having an issue with my iMach3 P2-S pendant since I installed it. Basically, the thing works great. I love it.

However, it seems to stop working randomly. I can use it for anywhere from a minute to hours when it seems reset back to the LinuxCNC screen and stops working with LinuxCNC. I've tried unplugging the USB cable and reattaching it, but it doesn't seem to help.

Any ideas?

TIA

I have a P4-S I abandoned a while ago due to flakey behavior and annoying USB lag/latency.  Solid, feels great, nice features... but unreliable for me.

I believe they are very sensitive to RF or EMI through the USB connection.  I've read a number of reports of similar issues - random resets.  One thread I read (maybe not on this board, cant remember) indicated the user could brick his iMach at will by stepping on a rubber anti-fatigue mat while holding the MPG.

When I had mine apart I realized the USB cable shield isn't connected to anything inside the MPG housing.  Not to the pcb ground, not to the case - just clipped short.  No way to dissipate static or anything inside (or outside) the MPG.  I'm not an electronics guru, but this didn't seem right.

If you are in love with it and don't feel like dealing with intermittent customer service from iMach, maybe add more ferrites to the cable.

Also - maybe - see if you can connect the cable shield to something that isn't powered on the PCB or housing.  And cross your fingers.

Thanks for your input. That makes sense. Is it worth trying some ferrites?

Are there other brands/models that are more reliable and easy to configure with LinuxCNC?

devils4ever wrote:

Thanks for your input. That makes sense. Is it worth trying some ferrites?

Are there other brands/models that are more reliable and easy to configure with LinuxCNC?
 

Clip-on ferrites are cheap on Amazon if you want to try it.

Is it worth trying?  Up to you.  I got fed up with the iMach even when it was working.  Because it uses USB - and possibly because of how it's programmed - there is a delay between when you stop moving the wheel and when the machine stops.  If you move the wheel fast back and forth, you can get to the point where the machine is moving opposite to the wheel direction.  Totally unsafe.

I got used to industrial machines with "direct" I/O MPG's and control buttons.  On those machines, there is zero perceptible delay between control input and machine response - even to the point where big machines will jump and jerk trying to keep up with aggressive commands.  Having experienced that, it's like the difference between driving an F1 car and a 1970's Oldmobile with worn-out suspension, spongy brakes, and a sloppy throttle cable.

My personal preference is a standard A/B quadrature encoder, connected directly to Mesa inputs. All critical controls (cyc start/stop feed hold, RRO/FRO/SRO, continuous jog buttons, etc) are also direct inputs.  No microprocessor, no cool features, no wireless/wifi.

I consider any of the Mesa SmartSerial boards to be 'direct I/O' as that method of connection is rock-solid and there's no human-perceptible lag or latency.  Which means a hand-held MPG with a 7i73 inside (for the digital display) will be be just as responsive as the panel-mounted stuff I built.

I have no experience with ethercat (native ethercat device or using a drive's I/O as GPIO), or any of the countless other clever methods folks have devised to expand IO by offloading through a USB or other bus of some sort.

spumco wrote:

I consider any of the Mesa SmartSerial boards to be 'direct I/O' as that method of connection is rock-solid and there's no human-perceptible lag or latency.  Which means a hand-held MPG with a 7i73 inside (for the digital display) will be be just as responsive as the panel-mounted stuff I built.

Well there are wireless pendants that wire into direct I/O (but they are not USB) that will give equivalent response
www.wixhctech.com/product/23.html
They use a lot of I/O but you can get versions that use digital inputs (which I have used) that save a few inputs
 

I've never experienced the lag/delay you described. My setup seems to respond instantly to the pendant.

I guess I'll give the ferrites a shot.